The conical sundial from Thyrrheion -- reconstruction and error analysis of a displaced antique sundial
This paper analyzes a fragmentary conical sundial now kept in the archeological museum at Thyrrheion (and mistakenly restored as a hollow sphere). The problem is one of determining the cardinal design parameters of a given object, a problem inverse to choosing such parameters and then constructing a sundial. One source of error is that antique sundials indicate temporal hours instead of local apparent time as modern sundials do. Forgetting this leads to errors in interpreting latitude made by previous contemporary interpreters; even though this difficulty was pointed out as early as 1846 (apparently in Greek in an Athenian publication).
scientific article; zbMATH DE number 1556786